Sheet transport and flattening apparatus

ABSTRACT

A flexible sheet transport has a flat bed support slidable past a guide bar having a set of vertical guide holes in which a set of rods slide and are downwardly urged to hold a sheet in contact with the moving flat bed support. The flat bed has cam surfaces for lifting the rods out of contact with the sheet to facilitate insertion and removal.

United States Patent [191 Georges [4 Jan. 14, 1975 1 SHEET TRANSPORT ANDFLATTENING APPARATUS [76] Inventor: Michael P. Georges, PO. Box 800,

Walpole, Mass. 02062 22 Filed: Dec. 20, 1972 21 Appl. No.: 316,760

Related U.S. Application Data [62] Division of Ser. No. 47,264, June 18,1970, Pat. No.

[52] U.S. Cl. 271/3, 271/267 [51] Int. Cl B65h 5/04 [58] Field of Search271/54, 55, 3, 8, 63, 48, 271/50, 58, 60, 84,45; 35/48 B; 355/72, 75,76; 248/361 [56] References Cited UNITED STATES PATENTS 1,209,91212/1916 Waite ..271/58 1,530,275 3/1925 Meamone 271/50 2,196,240 4/1940Whitehead... 271/54 2,495,887 1/1950 Bumstead 355/76 3,412,484 11/1968Evans et a1 35/48 B Primary ExaminerEvon C. Blunk AssistantExaminer-Bruce H. Stoner, Jr.

Attorney, Agent, or FirmDike, Bronstein, Roberts, Cushman & Pfund [57]ABSTRACT A flexible sheet transport has a flat bed support slidable pasta guide bar having a set of vertical guide holes in which a set of rodsslide and are downwardly urged to hold a sheet in contact with themoving flat bed support. The flat bed has cam surfaces for lifting therods out of contact with the sheet to facilitate insertion and removal 5Claims, 6 Drawing Figures PATENTEU JAN I 4l975 SHEET 20F 2 I q I k SHEETTRANSPORT AND FLATTENING APPARATUS RELATED APPLICATION This applicationis a division of my copending application Ser. No. 47,264, filed June18, 1970,.now US. Pat. No. 3,722,111.

BACKGROUND OF THE INVENTION This invention relates to electronicexamination paper test scoring devices of the type wherein theexamination is multiple-choice type and the test score is obtained bycomparing the pattern of multiple-choice answers selected and placed bythe student onto a test answer sheet with the correct answer patterncontained in a master answer device. Devices for grading papers based onthis general arrangement are well known and range from the largeautomatic machines for grading large numbers of examination papers athigh speed, such as the device described in US. Pat. No. 3,050,248, tovarious smaller machines adapted for use in the individual classroomwherein the examination papers are manually fed through the gradingstation.

The present invention relates to the smaller type machine thatpreferably uses conventional 8 /2 X 11 inch size test answer sheets andis adapted for use in the individual classroom or in a central office ofa smaller school with the operation being convenient mechanically andyet rapid and reliable so as to permit the individual teachers to gradethe papers for a days examination of all his students in a very briefperiod of time, while at the same time providing economy and reliabilitywhich is necessary to encourage the widespread adoption of such a devicein smaller school entities.

In the preferred form the examination paper and the scoring sensors arelaid out in strictly rectilinear fashion so that there is no unusualconfiguration of the sheet as far as offsetting columns of answers or ofthe detectors for the various columns thereby eliminating the necessityfor an abnormal marking pattern as is the case where staggered rows ofanswer columns are used. Further, the preferred form uses a set of photodetector devices having a latching characteristic and is employed sothat plural columns of questions containing multiple answers in each roware detected simultaneously as the row passes beneath the sensor row andby means of an electronic scan the incorrect and omitted answers areread from the scanned row during the interval when the next row ofanswers is moving to the sensor position. The speed of operation of thedevice is such that a simple in and out movement of the answer sheetpast the sensor row accomplishes a complete page scan and answertotalizing thereby giving the teacher the results of an individual paperwith extreme speed and simplicity of operation.

The object of the invention therefore is to provide a paper transportsuch as may be used in a high density examination paper using smallresponse marks and that is easy and convenient for the student to use,which is graded in a grading machine which accommodates the same therebyproviding a multiple-choice examination paper grading system whichpermits more examination questions to be answered in a conventionalsize, for example, 8% X 11 inch test paper than has heretofore beenpossible in a small low cost system. The optics of the apertures in thesystem are so arranged that extremely high accuracy of grading isobtained with a considerable tolerance latitude permitted in thephysical alignment of the parts. Thus the unit is well adapted for useby the everyday teacher at the end of the class period who can operatethe device with confidence although they do not possess any particularskill in aligning and feeding the examination papers through the device.

IN THE DRAWINGS FIG. 1 is a perspective view of one preferredarrangement of the paper grading machine with an examination paper and apermanent master answer-aperture plate shown in place for operation.

FIG. 2 is a view along the same lines as FIG. 1, with cover removed toshow various internal features of the device.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention comprises ahousing 11 having a front panel 12, upon which a numerical indicator 13is supported. The indicator 13 provides a readout of the test score andmay conveniently consist of a window through which numerals of a pair ofelectronic indicator tubes appear. Also mounted on the panel are on-offswitch 14 and pilot light 15.

The front panel contains a sliding support bed or carriage 16 which ismounted on a conventional drawer extension slide assembly 17 so as topermit the'support bed 16 to be fully extended as shown to receive anexamination paper or test answer sheet 18 thereon. The examination paperis positioned by a series of pins 19 and a paper stop in the form of anelongated slotted bar 21. The examination paper 18 rests upon and issupported by a rigid master answer-aperture plate 22. Theanswer-aperture plate 22 is mounted on the support bed frame 16 andaligned properly within the positioning boundaries l9 and 21 on thesupport bed frame 16 and is opaque except for the apertures 49 and 47.Alternatively, a transparent support plate could be used covered by anopaque surface with the appropriate aperture pattern. Thus with theanswer-aperture plate 22 aligned with and the examination paper 18 inplace be: tween the positioning posts 19 and the edge of the paperpositioning bar 21 assures that the aperture plate 22 and examinationpaper 18 are in appropriate registry in relation to the design centersand as will hereinafter appear provides sufficiently accurateregistration to assure uniform light detection properties during thesensing operation.

The support bed 16 is capable of being slid into the housing 11 on theextension slide assembly 17 by holding the handle 23 and the procedurefor grading a paper is to place the examination paper 18 onansweraperture plate 22 as shown in FIG. 1, pushing the support bed orcarriage l6 completely into the housing 11, and withdrawing it again tothe position shown in FIG. 1. In doing this operation the examinationpaper is graded and the correct test score appears at the indicatorwindow 13. During the scanning of the examination paper in order tomaintain optical uniformity and to prevent light leakage around theexamination paper apertures the examination paper 18 must be kept flatand in reasonable contact with the aperture plate 22 in the vicinity ofthe photo sensing area. As the sliding motion of the support bed 16takes place a series of light weight Teflon rods 24 which are looselysupported in vertical holes in a bar 20 act as weights to hold theexamination paper 18 flat against the top surface of the answer-apertureplate 22 at the photo sensing area without unduly weighting the paper orhaving any tendency to bind, buckle or otherwise distort the thin lighttransmissive sheet on which the examination paper 18 is printed.

Referring now to FIG. 2, the interior construction details are shownwhich include a second bar 25 having a series of vertical holes thereinin which are loosely mounted a second series of light Teflon rods 26fitted to act as a paper flattener in sliding contact with the surfaceof the examination paper 18. On the front surface of the bar 25 aremounted a plurality of lamps 27 which project a beam downwardly, theaxis of which is aligned with the reception aperture of photo detectordevices 28 and 48. The actual light transmission between the lamps 27and the photodetector devices 28 and 48 is through a rectangularaperture 29 in a bar 31 which covers the photo detectors 28 and 48throughout its length. This rectangular aperture cooperates with thepredetermined shape of the apertures in examination paper 18 andaperture plate 22 to eliminate excessive light leakage between adjacentapertures in both the horizontal and vertical directions. To aid ineliminating this misdirected light leakage the top surface of the bar 31which covers the photodetectors 28 and 48 and contains apertures 29 isplaced as close as reasonable manufacturing tolerances permit to thebottom surface of the aperture plate 22. This technique masks off givenareas and thereby cuts down on the light acceptance area and the lightacceptance angle to the photodetector devices 28 and 48. In the viewshown in FIG. 2 the bar 31 is broken away at the left hand end todisclose the general position of the photodetector devices 28. It willbe noted in FIG. 2 that the paper flattening rods 26 are aligned in arow parallel and to the rear of the row of lamps 27 and by referringback to FIG. 1 it will be recognized that the row of paper flatteningrods 24 is aligned on the front of the row of lamps 27. Thus the alignedlamps 27 and photo detectors 28 constitute a sensor row which is flankedon both sides by the rows of paper flattening'rods 24 and 26 therebyholding the examination paper in close contact with the aperture plate22 at the photosensing area during the transit of the alignedexamination paper and answer-aperture plate between the row of lamps 27and the row of rectangular apertures 29.

The paper stop bar 21 is provided with a downwardly sloping edge 32which acts to quickly lead into position and to keep the forward edge ofthe examinaton paper down in contact with the answer-aperture plate 22along the paper stop bar edge. Other configurations for holding down theforeward edge of the examination paper may be used such as clips or, asillustrated in FIG. 1, a long horizontal slot 34 in the paper stop bar21. The bar 21 is also provided with a plurality of sloping slots 30which are positioned in alignment with the rods 24 and 26. The lowerends of the rods 24 and 26 have rounded ends thereby providing a camaction when engaged with the bottom surface of the slots 30 to lift therods out of the way as the paper stop bar 21 slides underneath the bars20 and 25 in which the rods are slidably mounted. When the support bed16 is fully extended outside the housing 1 1 the rods 24 and 26 rest onthe paper stop bar 21 out of the way of an examination paper 18 that isto be inserted for scoring and later removed. In order to record a scorethe examination paper 18 is inserted onto the support bed 16, thesupport bed 16 and examination paper 18 are pushed into the housing 1 lto the closed and fully retracted position and then pulled out of thehousing 11 into the fully extended position. As the examination paper 18is pushed inward the rods 24 and 26 come down onto the paper toaccomplish their flattening action and later retract out of the way asthe examination paper is pulled out of the housing 11 for removal. Asthe examination paper 18 goes inward its leading edge is held down bythe downwardly sloping edge 32 or by other means for accomplishing thesame task so that the lower rounded ends of rods 24 and 26 can enterover the examination paper leading edge without hitting it. Other meansof lowering the rods 24 and 26 onto the examination paper 18 withouthitting against the examination paper leading edge and later liftingthese same rods 24 and 26 off the examination paper 18 and out of theway may be used. Except for controlled exposing to light throughapertures, the photo detector devices 28 and 48 must be kept coveredfrom the lamps 27. The paper stop bar 21 acts in a light shieldingfunction as an extension of the aperture plate 22 and keeps lightemitting from the lamps 27 from projecting onto the photo detectordevices 28 and 48 when the support bed 16 is fully extended out of thehousing 11. At the end of the inward travel of the slides 17 the supportbed 16 contacts a microswitch actuator 33 which provides a clear orreset signal to the electronic visual display devices which appear atthe window 13. Thus the operation of the photo detector devices 28during the inward travel of the support bed 16 is cleared and theexamination paper is graded during the withdrawal of the support bed 16thereby giving the final answer readout when the examination paper isonce again in the position shown in FIG. 1 and ready to be removed fromthe answer-aperture plate 22 by the teacher.

The extremely simple arrangement for examination grading shown provideshigh reliability and accuracy with the line by line photo sensing of aplurality of answers in the columns of the examination paper where eachlight transmission aperture is permitted to sense the necessary lightsignal from the lamps 27 as the row of combined photodetector apertures46 and 49 passes the sensor row.

Although test answer sheet scanning by manually moving the slide hasbeen disclosed this motion can be motorized or other modifications canbe made by those skilled in the art without departing from the scope ofthe invention as defined in the appended claims.

I claim:

1. A flexible sheet transport and sheet flattening device comprising:

a. a flat bed support for a thin flexible sheet;

b. means for translating said flat bed support to move substantiallyhorizontally past a transverse line;

c. a guide bar positioned above and generally parallel to saidtransverse line and having a set of substantially vertical guide holestherein;

(1. a set of rods slidably supported and downwardly urged in said set ofguide holes and supported on said flat bed support as it moves past saidtransverse line to maintain said flexible sheet in substantial contactwith said support in the vicinity of said transverse line and e. meanscarried by said flat bed support for contacting and automaticallylifting said rods from contact with said flat bed support at apredetermined position thereof to facilitate insertion and removal ofsaid sheets without contacting said rods.

2. A device according to claim 1 in which said means for automaticallylifting said rods from contact with said flat bed support comprises: anend stop in the form of a transverse plate at one end of said support toprovide an edge against which the edge of said flexible sheet can abutt,said edge containing a set of slots with inclined plane bottom surfacesand being aligned with said set of rods to lift said rods when saidsupport is moved to position said plate at said transverse line, saidrods having rounded ends to provide a smooth transition surface as thesaid rods enter onto the said end stop inclined slots.

3. A device according to claim 2 and including a second guide bar andset of rods slidable therein located on the opposite side of saidtransverse line to bear on said flexible sheet on both sides of saidtransverse line.

4. Apparatus according to claim 2 in which said edge of said plate isinclined to provide a downwardly sloping surface for guiding the forwardedge of a sheet placed on said support.

5. Apparatus according to claim 4 in which said downwardly slopingsurface terminates in a horizontal slot for retaining said forward edgeof said sheet.

1. A flexible sheet transport and sheet flattening device comprising: a.a flat bed support for a thin flexible sheet; b. means for translatingsaid flat bed support to move substantially horizontally past atransverse line; c. a guide bar positioned above and generally parallelto said transverse line and having a set of substantially vertical guideholes therein; d. a set of rods slidably supported and downwardly urgedin said set of guide holes and supported on said flat bed support as itmoves past said transverse line to maintain said flexible sheet insubstantial contact with said support in the vicinity of said transverseline and e. means carried by said flat bed support for contacting andautomatically lifting said rods from contact with said flat bed supportat a predetermined position thereof to facilitate insertion and removalof said sheets without contacting said rods.
 2. A device according toclaim 1 in which said means for automatically lifting said rods fromcontact with said flat bed support comprises: an end stop in the form ofa transverse plate at one end of said support to provide an edge againstwhich the edge of said flexible sheet can abutt, said edge containing aset of slots with inclined plane bottom surfaces and being aligned withsaid set of rods to lift said rods when said support is moved toposition said plate at said transverse line, said rods having roundedends to provide a smooth transition surface as the said rods enter ontothe said end stop inclined slots.
 3. A device according to claim 2 andincluding a second guide bar and set of rods slidable therein located onthe opposite side of said transverse line to bear on said flexible sheeton both sides of said transverse line.
 4. Apparatus according to claim 2in which said edge of said plate is inclined to provide a downwardlysloping surface for guiding the forward edge of a sheet placed on saidsupport.
 5. Apparatus according to claim 4 in which said downwardlysloping surface terminates in a horizontal slot for retaining saidforward edge of said sheet.